Hello all.
First off, thank you very much to anyone that posts advice to people. I've spent a lot of time on this amazing website and have probably read one of your comments at one point!

I was hoping someone could give me some guidance with my upgrade.
I'm about to upgrade my childrens 6v single rear wheel motor quad bike (non fisher price) to a 12v double rear wheel drive with either a 12v or 12v+6v battery. I am upgrading the wire to 10awg.

Could someone please tell me:-
What the circuit board is below?
Will I need to upgrade it?
Will I need one for each motor?

Please "fisherprice" any answers and imagine you are talking to one of your children!